diff --git a/python/trx/radio_if.py b/python/trx/radio_if.py
new file mode 100644
index 0000000..c162f69
--- /dev/null
+++ b/python/trx/radio_if.py
@@ -0,0 +1,175 @@
+#!/usr/bin/env python2
+# -*- coding: utf-8 -*-
+
+# GR-GSM based transceiver
+# Follow graph implementation
+#
+# (C) 2016-2017 by Vadim Yanitskiy <axilirator@gmail.com>
+#
+# All Rights Reserved
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+import pmt
+import time
+import grgsm
+import osmosdr
+
+from math import pi
+
+from gnuradio import blocks
+from gnuradio import gr
+
+class RadioInterface(gr.top_block):
+	# PHY specific variables
+	samp_rate = 2000000
+	shiftoff = 400e3
+	subdev_spec = "" # TODO: use it
+	device_args = ""
+	fc = 941.6e6 # TODO: set ARFCN to 0?
+	gain = 30
+	ppm = 0
+
+	# Application state flags
+	trx_started = False
+	fc_set = False
+
+	def __init__(self, phy_args, phy_subdev_spec,
+				phy_sample_rate, phy_gain, phy_ppm,
+				trx_remote_addr, trx_base_port):
+		print("[i] Init Radio interface")
+
+		# TRX block specific variables
+		self.trx_remote_addr = trx_remote_addr
+		self.trx_base_port = trx_base_port
+
+		# PHY specific variables
+		self.subdev_spec = phy_subdev_spec
+		self.samp_rate = phy_sample_rate
+		self.device_args = phy_args
+		self.gain = phy_gain
+		self.ppm = phy_ppm
+
+		gr.top_block.__init__(self, "GR-GSM TRX")
+		shift_fc = self.fc - self.shiftoff
+
+		##################################################
+		# PHY Definition
+		##################################################
+		self.phy = osmosdr.source(
+			args = "numchan=%d %s" % (1, self.device_args))
+
+		self.phy.set_bandwidth(250e3 + abs(self.shiftoff), 0)
+		self.phy.set_center_freq(shift_fc, 0)
+		self.phy.set_sample_rate(self.samp_rate)
+		self.phy.set_freq_corr(self.ppm, 0)
+		self.phy.set_iq_balance_mode(2, 0)
+		self.phy.set_dc_offset_mode(2, 0)
+		self.phy.set_gain_mode(False, 0)
+		self.phy.set_gain(self.gain, 0)
+		self.phy.set_if_gain(20, 0)
+		self.phy.set_bb_gain(20, 0)
+		self.phy.set_antenna("", 0)
+
+		##################################################
+		# GR-GSM Magic
+		##################################################
+		self.blocks_rotator = blocks.rotator_cc(
+			-2 * pi * self.shiftoff / self.samp_rate)
+
+		self.gsm_input = grgsm.gsm_input(
+			ppm = self.ppm, osr = 4, fc = self.fc,
+			samp_rate_in = self.samp_rate)
+
+		self.gsm_receiver = grgsm.receiver(4, ([0]), ([]))
+
+		self.gsm_clck_ctrl = grgsm.clock_offset_control(
+			shift_fc, self.samp_rate, osr = 4)
+
+		self.gsm_trx_if = grgsm.trx(self.trx_remote_addr,
+			str(self.trx_base_port))
+
+		##################################################
+		# Connections
+		##################################################
+		self.connect((self.phy, 0), (self.blocks_rotator, 0))
+		self.connect((self.blocks_rotator, 0), (self.gsm_input, 0))
+		self.connect((self.gsm_input, 0), (self.gsm_receiver, 0))
+
+		self.msg_connect((self.gsm_receiver, 'measurements'),
+			(self.gsm_clck_ctrl, 'measurements'))
+
+		self.msg_connect((self.gsm_clck_ctrl, 'ctrl'),
+			(self.gsm_input, 'ctrl_in'))
+
+		self.msg_connect((self.gsm_receiver, 'C0'),
+			(self.gsm_trx_if, 'bursts'))
+
+	def check_available(self):
+		return self.fc_set
+
+	def shutdown(self):
+		print("[i] Shutdown Radio interface")
+		self.stop()
+		self.wait()
+
+	def get_args(self):
+		return self.args
+
+	def set_args(self, args):
+		self.args = args
+
+	def get_fc(self):
+		return self.fc
+
+	def set_fc(self, fc):
+		self.phy.set_center_freq(fc - self.shiftoff, 0)
+		self.gsm_input.set_fc(fc)
+		self.fc_set = True
+		self.fc = fc
+
+	def get_gain(self):
+		return self.gain
+
+	def set_gain(self, gain):
+		self.phy.set_gain(gain, 0)
+		self.gain = gain
+
+	def get_ppm(self):
+		return self.ppm
+
+	def set_ppm(self, ppm):
+		self.rtlsdr_source_0.set_freq_corr(ppm, 0)
+		self.ppm = ppm
+
+	def get_samp_rate(self):
+		return self.samp_rate
+
+	def set_samp_rate(self, samp_rate):
+		self.blocks_rotator.set_phase_inc(
+			-2 * pi * self.shiftoff / samp_rate)
+		self.gsm_input.set_samp_rate_in(samp_rate)
+		self.phy.set_sample_rate(samp_rate)
+		self.samp_rate = samp_rate
+
+	def get_shiftoff(self):
+		return self.shiftoff
+
+	def set_shiftoff(self, shiftoff):
+		self.blocks_rotator.set_phase_inc(
+			-2 * pi * shiftoff / self.samp_rate)
+		self.phy.set_bandwidth(250e3 + abs(shiftoff), 0)
+		self.phy.set_center_freq(self.fc - shiftoff, 0)
+		self.shiftoff = shiftoff